A new convergent algorithm to approximate potentials from fixed angle scattering data

We introduce a new iterative method to recover a real compact supported potential of the Schr\"odinger operator from their fixed angle scattering data. The method combines a fixed point argument with a suitable approximation of the resolvent of the Schr\"odinger operator by partial sums associated to its Born series. Convergence is established for potentials with small norm in certain Sobolev spaces. As an application we show some numerical experiments that illustrate this convergence.Comment: 25 pages, 6 figure

NU-WRF Development and Support at NASA GSFC

The NASA Unified WRF modeling system (NU-WRF) is an observation driven framework that combines WRF-ARW with Goddard developed radiation, microphysics, aerosols and land information system (LIS) packages. NU-WRF can be used for simulating aerosols and land use effects on a variety of weather events. This poster will present a description of the modeling system including updates and future plans

Development of a high-performance W-band duplexer for plasma diagnosis using a single band with dual circular polarization

Discrepancia entre la información que aparece en el artículo que indica que el copyright es de Elsevier, y la información que aparece en la página de la revista y en el Copyright Clearance Center que indican © 2019 The Authors. Published by Elsevier B.V., así como que el artículo está publicado en Open Access under a Creative Commons licenceThis work presents the design and experimental validation of a high performance, compact, waveguide duplexer operating from 91.5 to 96.5 GHz for its integration in diverse W-band microwave equipment as in plasma diagnosis applications. It uses a single frequency band, with two signals discriminated by different orthogonal circular polarization, which is generated by means of a septum orthomode transducer (OMT) polarizer. Moreover, this component is optimized loaded with the horn antenna for improving the overall system performance. It is explained how these two components are integrated into a very compact duplexer, designed using efficient numerical algorithms. The manufacturing process by mean of high precision milling, and including electrical discharge machining (EDM) has led to excellent performances. The measured return loss level and isolation are higher than 30 dB, and the insertion loss level is below 0.3 dB. Finally, the key parameter in this device, which reflects the symmetry in the manufacturing process, i.e., the axial ratio, is lower than 0.6 dB for both polarizations, an excellent result showing the potential of the presented designThis work was supported by the Spanish government under grants (ADDMATE) TEC2016-76070-C3-1/2-R (Agencia Estatal de Investigación, Spain, Fondo Europeo de Desarrollo Regional: AEI/FEDER/UE) and the program of Comunidad de Madrid, Spain S2013/ICE-3000 (SPADERADARCM

Information and Communication Technologies (ICTS) as a Tool for Intercultural Education. A collaborative experience in secondary education in Tlapa de Comonfort, Guerrero, Mexico

This paper discusses the collaborative experience of creating educational materials for a secondary school in Tlapa de Comonfort, Guerrero, México. In this school, students from Nahuatl, Tun savi, Me'phaa and Spanish speaking communities live and learn together. The intercultural context provides challenges for science education that we sought to address. The use of collaborative technologies in science classes has made visible the cultural diversity in the classroom, helping students and teachers recognize themselves as active agents in the construction of common knowledge and in sharing their\ud knowledge. This experience also shows the importance of ICTs as technologies of expression that reinforce individual and collective identity in intercultural contexts

POSITION PAPER - pFLogger: The Parallel Fortran Logging Framework for HPC Applications

In the context of high performance computing (HPC), software investments in support of text-based diagnostics, which monitor a running application, are typically limited compared to those for other types of IO. Examples of such diagnostics include reiteration of configuration parameters, progress indicators, simple metrics (e.g., mass conservation, convergence of solvers, etc.), and timers. To some degree, this difference in priority is justifiable as other forms of output are the primary products of a scientific model and, due to their large data volume, much more likely to be a significant performance concern. In contrast, text-based diagnostic content is generally not shared beyond the individual or group running an application and is most often used to troubleshoot when something goes wrong. We suggest that a more systematic approach enabled by a logging facility (or 'logger') similar to those routinely used by many communities would provide significant value to complex scientific applications. In the context of high-performance computing, an appropriate logger would provide specialized support for distributed and shared-memory parallelism and have low performance overhead. In this paper, we present our prototype implementation of pFlogger - a parallel Fortran-based logging framework, and assess its suitability for use in a complex scientific application

Light‐Emitting Diodes: Progress in Plant Micropropagation

In commercial micropropagation laboratories, the light source is one of the most important factors controlling plant morphogenesis and metabolism of plant cells and tissue and organ cultures. Lamp manufacturers have begun to rate lamps specifically for plant needs. The traditional light source used for in vitro propagation is fluorescent lamps (FLs). However, power consumption in FL use is expensive and produces a wide range of wavelengths (350–750 nm) unnecessary for plant development. Light‐emitting diodes (LEDs) have recently emerged as an alternative for commercial micropropagation. The flexibility of matching LED wavelengths to plant photoreceptors may provide more optimal production, influencing plant morphology and chlorophyll content. Although previous reports have confirmed physiological effects of LED light quality on morphogenesis and growth of several plantlets in vitro, these study results showed that LED light is more suitable for plant morphogenesis and growth than FLs. However, the responses vary according to plant species. This chapter describes the applications and benefits of LED lamps on chlorophyll in plant micropropagation. Two study cases are exposed, Anthurium (Anthurium andreanum) and moth orchids (Phalaenopsisis sp.), both species with economic importance as ornamental plants, where LEDs have a positive effect on in vitro development and chlorophyll content